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S. N. GARVALHO. APPARATUS FOR SUPERHEATING STEAM.

Patented Jan. 3, 1860.

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UNITED- STATES PATENT OFFICE.

SOLOMON N. (,IARVALHO,- OF BALTIMORE, MARYLAND, ASSIGNOR TO HIM- SELFAND L. BOWEN.

APPARATUS SUPERHEATING STEAM.

Specification forming part of Letters Patent No. 26,781, dated January3, 1860.

To all whom it may concern:

Be it known that I, SOLOMON N. CARVALHO, of the city of Baltimore, inthe State of Maryland, have invented certain Improvements for Increasingthe Power of Steam; and I do hereby declare the following to be a full;clear, and exact description of the same, ref- .erence being bad to theaccompanying drawings and to the letters and marks thereon.

Various eiforts have been made to increase the power of steam bysuperheating it. The great obstacle'to the permanency of allarrangements of means for superheating arises from the rapidox'idization of the metal exposed to the high degree of heat on its onesurface and to the gases of the decomposed steam on the other surface,as the steam under the necessary degree of heat will part with itsoxygen to the metal and with its hydrogen to the medium aboutit,whatever that medium or element may be. The metal constituting theheating tubes or chambers is rapidly destroyed by its exposure to theheat and oxygen.

My inventionhas for its object the removal of the obstacle named, andalso the increasing of the power of steam economically; and my inventionconsists in passinga continuous supply of ordinary steam from the boilerthrough a cast-iron retort containing equal parts of the black protoxideof iron and ircn turnings, the retort being placed either in the furnaceof the boiler or a separate furnace.

The drawings forming part of this specification show one arrangement ofmeans for carrying out my invention; but, as is evident, otherarrangements may be substituted for that shown without departing fromthe nature and character of my invention.

Figure l of the drawings represents a longitudinal section of ahorizontal tubular boiler; Fig. 2, a front view of a like boiler, andFig. 3 a longitudinal sectional View of aretort or superheating-chamberwith the ends of the egress and ingress pipes attached.

In Figs. 2 and 3 the retort or superheatingchamber is represented ascharged with the metal heretofore named.

In each of the several figures where like parts are indicated the likeletters are used.

0. marks the waterspace of the boiler; b, fire-space; c, steam-space;(Z, steam-dome; e,

fire-chamber; f, grate-surface; g, the retort or supe'rheating chamber;h h steam-conductin g pipes; ii, check-valves in the steam-pipes, and jj controlling-valves.

If the superheating chamber or retort be charged with about equal partsof iron tumings and the protoxide of iron, and the steam being generatedin the boiler be allowed to pass into the retort, as it will by themeans herein set out, as the steam comes in contact with the metal itwill be, necessarily, distributed gpon 'an extensive heating-surfacemuch greater than the retort would afford by itself, or withoutthefragments and turnings of metaL At an ordinary degree of temperature thesteam would pass through the retort and receive a limited increase ofheat,

and without materially affecting the metal of the retort; but upon suchan increase of heat as would constitute superheating fully the steamcoming in contact with the iron becomes decomposed, and is resolved intooxygen and hydrogen gases, and the retort would be rapidly destroyed.When, however, the retort has been charged with the metal turnings andpro-toxide of iron, here named, it has been ascertained that theseactions follow: the metallic iron absorbs the oxygen, setting thedydrogen free, while the hydrogen at the same temperature passing overthe protoxide' of iron convertsit again into its metallic state, settingfree pure steam. As the process of passing in the steam and decomposingit continues, the metallic iron parts, with the oxygen it had absorbedor combined with, and in its turn takes the place of the protoxide,while the protoxide takes the place of the metallic 'ron, and thiscompensating action continu for an indefinite period of time, or

' for such period of time as the use of the material and thecircumstances attending itcontrol or govern. Under these actions themetal of the retort is not materially aifected, the exposure of theturnings and oxide of iron to the gases being so much greater relievesin a great measure the interior surface of the retort from corrosion. Inthe changes which thus take place it is believed that the latent heat ofthe steam is liberated and becomes sensible heat. Under the arrangementshown by the drawings the steam is conveyed by its own pressure into theretort through the pipe h, placed outside of the furnace, uniting withthe top of the boiler and with the bottom of the retort, the pipe beingsupplied with a check-valve, 1', which allows the steam to pass freelyinto the retort, but which prevents the steam from returning from theretort by the way it entered. "A secondpipe, h, one-third or more largerin diameter than the first, is connected with the top of the retort-andthe steam-dome of the boiler. This pipe is also furnished with acheck-valve, 'i', which will admit the steam after it has'been passedthrough the heated retort into the steam-dome, but will prevent thesteam from passing into theretort from the dome. Both of these pipes arefurnished with stop-cocks jj', to shut ofi all connection with theboiler at a moments notice. Try-cocks can also be placed in these pipes.The use of the material contained in the retort insures the return ofreal steam in its exact chemical combinations from the retort into thesteam-dome, and not hydrogen gas, which would be the case if the retortalone be used.

The retort or superheating-chamber i s' shown as being connected byflanges to the ends of the pipes, which manner of connecting allows ofthe ready removal and replacing of the retort; but, as is evident, theconnection may be made by any other convenient means. It is also shownas being placed in the back part of the furnace, while it may be placedat the .sides, top, or in other parts; or it may be placed in a furnaceexterior to the boiler, and it may be so constructed as to be of anydesirable shape or form or a series of forms. Insteadof conveying thesteam from the superheating-chamber to the steam-dome, it may in someinstances he more desirable or convenient to convey it from the chamberto the cylinder of the engine.

It will benoticed that perforated plates are placed at each end of theretort or chamber to keep the pieces of metal and turnings in position;but in many cases these may bedispensed with. T The pieces of metal andturnings I prefer to place in alternating layers; but they may be put inthe chamber irregularly, or the one may occupy the one half of thechamber and the other the other half.

In addition to the great security which this invention offers fromexplosion of boilers and connections where superheating of steam isresorted to, and where in many instances the explosion may be attributedto the existence of the hydrogen gas, the saving of fuel makes theinvention very valuable, as it is estimated on the results ofexperiments made that the economy of fuel is about from forty to fiftyper cent.

What I claim as my invention is- 1. subjecting steam While undergoingthe superheat-ing process to the action of the metals herein named, asand for the purposes set forth. 1

2. The arrangement of the pipes, the valves, and the retort or itsequivalent for conveying from, heating, and returning to the boiler orits connecting steam-dome the steam, sub stantially as described.

This specification signed this 9th day of December, 1859.

i S. N. CARVALHQ. Witnesses:

MARCUS P. NORTON, T. T. EVERETT.

